Method for sequencing and marking spatial discrete grid surfaces and counting simulation uniformity

Abstract

A method for sequencing and marking spatial discrete grid surfaces and counting simulation uniformity is applied to simulation work of nozzle flow, temperature, pressure and the like and uniformity of a single combustion chamber comprising a large number of nozzles, and sequencing and marking work on the grid surfaces of the nozzles is completed through a python program. The method comprises the following steps of: performing simulation calculation on a plurality of nozzles, storing related contents as a single file of accompanying geometry and grids, reading the accompanying file through a python program after the simulation calculation work is completed, counting parameters such as speed, temperature and pressure on each marked grid surface and the distribution uniformity of the corresponding parameters under the grid surface, and finally obtaining the distribution uniformity of all the nozzles. Based on the method, whether the design and arrangement of the nozzles meet the design requirements or not is judged, and analysis and improvement are carried out.

Description

Technical Field

[0001] The invention relates to a method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity, and belongs to the technical field of liquid rocket engines. Background Art

[0002] With the rapid development of aerospace liquid rocket engine technology, the traditional combustion chamber nozzle arrangement can no longer meet the performance requirements. Therefore, the structural design of a single nozzle and the arrangement design of multiple nozzles are becoming more and more complex and diversified. One of the important development trends is that a single nozzle is miniaturized and contains more and smaller micro-channel outlets. With the miniaturization of nozzles, the number of nozzles has also increased significantly, often hundreds or thousands. At the same time, in order to avoid the high temperature near the nozzle outlet burning the burner and suppressing thermal acoustic oscillations, there are nozzles with different functions. These nozzles have different outlet types and are often not located on the same spatial plane. In general, the new combustion chamber nozzle has the following three characteristics in arrangement: 1. A single nozzle contains multiple outlets; 2. A single combustion chamber contains a large number of nozzles; 3. The nozzle outlets are often not located on the same spatial plane.

[0003] The design of nozzle arrangement is not arbitrary, and often needs to meet certain design requirements, such as uniformity or specific flow distribution. Therefore, designers urgently need to know whether the flow, pressure, temperature and uniformity of each nozzle outlet meet the design requirements. However, due to the lack of experimental measurement technology and cost considerations, it is usually difficult to obtain experimental data of such a large number of nozzles at each nozzle outlet position through experimental methods. Therefore, obtaining data on each nozzle outlet through simulation methods has become an important part of nozzle arrangement design.

[0004] The current mainstream general flow field simulation software such as Fluent, OpenFoam, etc. can calculate the velocity, pressure, temperature, etc. at each grid position in the flow field. This seems to solve the difficulties mentioned above, but the general software itself does not have corresponding functions to solve the above problems in one step. From the perspective of simulation, the simulation calculation only obtains the relevant data on the grid points near the nozzle outlet position. In fact, from the perspective of nozzle design sorting, these data are discrete and inconsistent with the distribution law of nozzle organization sorting, which requires further processing. At the same time, what we need to obtain is the statistics on the nozzle outlet surface rather than the original quantity of a single node.

[0005] Usually, in order to obtain the statistics on each nozzle, simulators often need to manually sort and name the nozzles of the original geometric model one by one, and then extract the statistics on each surface after the calculation is completed. As the size of nozzles decreases and the number increases sharply, the number of surfaces that need to be manually sorted and named has exploded. The simulator's work time has increased from minutes to hours, which is prone to errors and cannot meet the needs of rapid design iterations. Summary of the invention

[0006] The technical problem solved by the present invention is: in view of the problem that the traditional nozzle design technology in the current prior art has a high error rate and is difficult to meet the design requirements of liquid rocket engines, a method for sorting and marking spatial discrete grid surfaces and statistically simulating uniformity is proposed.

[0007] The present invention solves the above technical problems by the following technical solutions:

[0008] A method for sorting and marking spatial discrete grid surfaces and statistically analyzing simulation uniformity, comprising:

[0009] Establish geometric model for nozzle structure simulation analysis;

[0010] Divide the geometric model according to the fluid domain on the nozzle surface, filter the geometric surface set, sort and name them, and then store them as accompanying files;

[0011] Perform simulation calculations based on the accompanying file data, read the simulation calculation results to perform facet division, calculate the average simulation value of each facet after division, calculate the distribution uniformity and mass flow of each facet based on the average simulation value, integrate the calculated data statistics and store them as an accompanying file;

[0012] Calculate the uniformity of the statistical quantity distribution of each nozzle surface according to the accompanying files stored after integration;

[0013] According to the calculated distribution uniformity of the statistical quantities of each nozzle surface, the corresponding flow distribution and pressure drop of each nozzle surface, it is judged whether the nozzle structure corresponding to the current geometric model meets the design requirements.

[0014] The method to filter the geometric face collection is:

[0015] The geometric model is divided into the front section of the nozzle inlet, the nozzle inlet, the nozzle section, the nozzle outlet, and the rear section of the nozzle outlet according to the fluid domain on the nozzle surface;

[0016] Read the geometric faces of the front section of the nozzle inlet and the back section of the nozzle outlet, and record the geometric faces of the front section of the nozzle inlet as a collection of faces in , record the geometric faces read at the nozzle outlet as a collection of faces out, according to the geometric size relationship, the two sets are eliminated from the geometric faces that do not meet the size of the nozzle surface, and recorded as the set faces;

[0017] For collection faces in , collection faces out The size parameters of each geometric face in the set are divided into surrounding geometric faces, and the larger size parameters are divided into central geometric faces. The surrounding geometric faces and central geometric faces in each set are matched with circular features to obtain the reorganized set faces. in , reorganize the collection faces out ;

[0018] Read the fluid channel numbered j in the nozzle segment numbered i, and record the inlet and outlet surfaces as and Reorganize the collection faces according to the entry and exit faces in , reorganize the collection faces out Re-represent the data structure;

[0019] Reorganized collection faces after re-representation in , reorganize the collection faces out Determine the position of the center nozzle surface. If there is a center nozzle surface where the center nozzle is set Then mark the group name, if it does not exist, create a center nozzle surface containing the center nozzle Simultaneously name a mark or create a center nozzle face

[0020]

[0021] According to other geometrical surfaces and the central nozzle surface or The distance between the two geometric faces is classified as N k Ring Group or

[0022]

[0023] Select the surrounding geometric faces closest to the center nozzle face for sorting and naming, select any face in face_ring2 as the starting face for ring sorting and mark it after naming, and sort and name the remaining surrounding geometric faces in face_ring2 in a counterclockwise order;

[0024] For the geometric faces in face_ring2, select the geometric face closest to the ring sorting start face in the k-1th ring as the ring sorting start face, and sort the remaining geometric faces counterclockwise to complete the ring sorting and naming of all geometric faces;

[0025] The two types of nozzle surface sets are denoted as and Add geometric boundary features to each nozzle face and add the features to the collection faces. in and faces out Stored as data file.

[0026] For collection faces in , collection faces out The method for matching the annular features of the surrounding geometric surface and the central geometric surface is as follows:

[0027] The collection faces in N with larger size parameter i The central geometric faces are labeled as faces in1 , the size parameter is smaller N j The surrounding geometric faces are labeled as faces in2 , the collection faces in1 Each geometric face in the collection is in2 The geometric faces in the N j +1 geometric face matching, the next set is recorded as Recombination N i indivual For collection faces in , while recombining N i indivual For collection faces in ;

[0028] The collection faces out N with larger size parameter i The central geometric faces are labeled as faces out , the size parameter N is smaller j The surrounding geometric faces are labeled as faces out2 , the collection faces out1 Each geometric face in the collection is out2 The geometric faces in the N j +1 geometric face matching, the next set is recorded as Recombination N i indivual For collection faces out , while recombining N i indivual For collection faces out .

[0029] The collection faces includes N i ×2×(Nj +1) faces, N i is the number of nozzles, (N j +1) is the number of nozzle fluid channels; after re-expression:

[0030]

[0031] In the formula, is the center plane of nozzle i;

[0032]

[0033] In the formula, is the center plane of nozzle i.

[0034] The geometric boundary features are:

[0035] [face i,j ,area i,j ], area i,j for face i,j The radius of the largest inscribed circle, the coordinates of the center of the circle and the normal vector of the plane.

[0036] The method for integrating data statistics after each bin division is:

[0037] After reading the simulation result file, according to the naming file order, according to the geometric face set screening method, obtain each geometric face [face i,j ,area i,j ] on the statistical information;

[0038] According to the geometric boundary area of ​​the circular surface contained in the naming file i,j , divide each geometric surface into n face elements, read the preset relative coordinate file according to the coordinates of the divided nodes, and i,j Determine the center coordinates, diameter and normal vector to translate, scale and rotate the coordinates;

[0039] The simulation value X at the centroid position of each surface element i is read by interpolation method i , based on area A i The average simulation value of each facet is calculated by weighted method And calculate the average simulation value The distribution uniformity of X and mass flow

[0040] All data statistics are combined into format, and stored as corresponding accompanying files according to the number of nozzle surfaces stored.

[0041] The method for calculating the uniformity of the statistical distribution of each nozzle surface is:

[0042] Obtain the corresponding statistics on the j+1 faces of each nozzle i;

[0043] According to the uniformity calculation formula, the distribution uniformity of each statistical physical quantity on the central nozzle surface of each ring nozzle is obtained.

[0044] The same calculation method is used to determine the distribution uniformity of the remaining surface statistics after averaging them by surface;

[0045] The statistical physical quantities on the central nozzle surface of all nozzles are obtained, and the distribution uniformity is calculated. The distribution uniformity of the statistical quantities on the remaining surfaces after being averaged by the surface is determined by the same calculation method.

[0046] The distribution uniformity of each statistical physical quantity on the central nozzle surface of each ring nozzle Specifically:

[0047]

[0048] Wherein, the number of nozzles is N.

[0049] The calculation method of the distribution uniformity of the statistical physical quantity corresponding to the central nozzle surface of all nozzles is:

[0050]

[0051] When the reorganized collection faces are re-represented in Or reorganize the collection faces out Including the center nozzle surface When the center nozzle surface is named type_in_1_1_1, in represents the inlet, and the three digits represent the number of rings, the number of nozzle surface groups, and the center surface respectively;

[0052] Select any face in face_ring2 as the starting face for ring sorting and name it type_in_2_1_1, where in represents the inlet and the three digits represent the number of rings, the number of nozzle face groups, and the center face respectively.

[0053] The advantages of the present invention compared with the prior art are:

[0054] (1) The present invention provides a method for sorting and marking spatial discrete grid surfaces and statistically analyzing simulation uniformity, which can realize a method for quickly simulating and evaluating parameters such as flow rate and pressure at the inlet and outlet of each nozzle in a combustion chamber containing hundreds or thousands of nozzles. The method includes two types of innovative processing: pre-simulation processing and post-simulation processing. When there are tens of thousands of disordered grid surfaces in the thrust chamber containing information to be extracted, the surfaces are quickly sorted, classified and marked according to the design logic and applied to the simulation pre-processing method during the simulation calculation period, thereby realizing innovative processing of geometry during the simulation pre-processing period. The above work can be completed through a python program to meet the simulation work needs under a large number of nozzles.

[0055] (2) When the simulation software lacks the statistical multi-dimensional uniformity of hundreds or thousands of grid surfaces, the present invention proposes an API interface through the post-processing software, which completes the evaluation of the multi-dimensional simulation uniformity by writing a program. In the post-simulation processing period, innovative processing of the geometry is proposed to obtain the distribution uniformity of all nozzles and generate relevant files. Based on this method, it is judged whether the design and arrangement of the nozzles meet the design requirements, and then analysis and improvement are carried out, which can reserve filing and design space for existing design schemes. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A flow chart of the method for sorting, marking and statistically simulating uniformity of spatial discrete grid surfaces provided by the invention;

[0057] Figure 2 A simple schematic diagram of the nozzle fluid domain provided for the invention;

[0058] Figure 3 A schematic diagram of the fluid domains before and after the nozzle inlet after topological sharing provided by the invention;

[0059] Figure 4 A schematic diagram of the spatial distribution of the nozzle inlet and outlet surfaces provided for the invention;

[0060] Figure 5 A schematic diagram of the statistical discrete sampling division of the nozzle surface data provided by the invention; DETAILED DESCRIPTION

[0061] A method for sorting and marking spatial discrete grid surfaces and statistically analyzing simulation uniformity is applied to the simulation of nozzle flow, temperature, pressure, etc. and uniformity of a single combustion chamber containing a large number of nozzles. The sorting and marking of the nozzle grid surfaces are completed through a python program, and the relevant content is stored as a single file with accompanying geometry and grids. After the simulation calculation is completed, the accompanying file is read again through the python program to count the speed, temperature, pressure and other parameters on each marked grid surface and the distribution uniformity of the corresponding parameters under the grid surface, and finally the distribution uniformity of all nozzles is obtained, and relevant files are generated. Based on this method, it is judged whether the design and arrangement of the nozzles meet the design requirements, and analysis and improvement are carried out.

[0062] The method for sorting and marking the spatial discrete grid surface and statistically analyzing the simulation uniformity is as follows:

[0063] Establish geometric model for nozzle structure simulation analysis;

[0064] Divide the geometric model according to the fluid domain on the nozzle surface, filter the geometric surface set, sort and name them, and then store them as accompanying files;

[0065] Perform simulation calculations based on the accompanying file data, read the simulation calculation results to perform facet division, calculate the average simulation value of each facet after division, calculate the distribution uniformity and mass flow of each facet based on the average simulation value, integrate the calculated data statistics and store them as an accompanying file;

[0066] Calculate the uniformity of the statistical quantity distribution of each nozzle surface according to the accompanying files stored after integration;

[0067] According to the calculated distribution uniformity of the statistical quantities of each nozzle surface, the corresponding flow distribution and pressure drop of each nozzle surface, it is judged whether the nozzle structure corresponding to the current geometric model meets the design requirements.

[0068] The method to filter the geometric face collection is:

[0069] The geometric model is divided into the front section of the nozzle inlet, the nozzle inlet, the nozzle section, the nozzle outlet, and the rear section of the nozzle outlet according to the fluid domain on the nozzle surface;

[0070] Read the geometric faces of the front section of the nozzle inlet and the back section of the nozzle outlet, and record the geometric faces of the front section of the nozzle inlet as a collection of faces in , record the geometric faces read at the nozzle outlet as a collection of faces out , according to the geometric size relationship, the two sets are eliminated from the geometric faces that do not meet the size of the nozzle surface, and recorded as the set faces;

[0071] For collection faces in , collection faces outThe size parameters of each geometric face in the set are divided into surrounding geometric faces, and the larger size parameters are divided into central geometric faces. The surrounding geometric faces and central geometric faces in each set are matched with circular features to obtain the reorganized set faces. in , reorganize the collection faces out ;

[0072] Read the fluid channel numbered j in the nozzle segment numbered i, and record the inlet and outlet surfaces as and Reorganize the collection faces according to the entry and exit faces in , reorganize the collection faces out Re-represent the data structure;

[0073] Reorganized collection faces after re-representation in , reorganize the collection faces out Determine the position of the center nozzle surface. If there is a center nozzle surface where the center nozzle is set Then mark the group name, if it does not exist, create a center nozzle surface containing the center nozzle Simultaneously name a mark or create a center nozzle face

[0074]

[0075] According to other geometrical surfaces and the central nozzle surface or The distance between the two geometric faces is classified as N k Ring Group or

[0076]

[0077] Select the surrounding geometric faces closest to the center nozzle face for sorting and naming, select any face in face_ring2 as the starting face for ring sorting and mark it after naming, and sort and name the remaining surrounding geometric faces in face_ring2 in a counterclockwise order;

[0078] For the geometric faces in face_ring2, select the geometric face closest to the ring sorting start face in the k-1th ring as the ring sorting start face, and sort the remaining geometric faces counterclockwise to complete the ring sorting and naming of all geometric faces;

[0079] The two types of nozzle surface sets are denoted as and Add geometric boundary features to each nozzle face and add the features to the collection faces. in and faces out Stored as data file.

[0080] For collection faces in , collection faces out The method for matching the annular features of the surrounding geometric surface and the central geometric surface is as follows:

[0081] The collection faces in N with larger size parameter i The central geometric faces are labeled as faces in1 , the size parameter N is smaller j The surrounding geometric faces are labeled as faces in2 , the collection faces in1 Each geometric face in the collection is in2 The geometric faces in the N j +1 geometric face matching, the next set is recorded as Recombination N i indivual For collection faces in , while recombining N i indivual For collection faces in ;

[0082] The collection faces out N with larger size parameter i The central geometric faces are labeled as faces out , the size parameter N is smaller j The surrounding geometric faces are labeled as faces out2 , the collection faces out1 Each geometric face in the collection is out2 The geometric faces in the N j +1 geometric face matching, the next set is recorded as Recombination N i indivual For collection faces out , while recombining N i indivual For collection faces out .

[0083] The collection faces includes N i ×2×(N j +1) faces, N i is the number of nozzles, (N j +1) is the number of nozzle fluid channels; after re-expression:

[0084]

[0085] In the formula, is the center plane of nozzle i;

[0086]

[0087] In the formula, is the center plane of nozzle i.

[0088] The geometric boundary features are:

[0089] [face i,j ,area i,j ], area i,j for face i,j The radius of the largest inscribed circle, the coordinates of the center of the circle and the normal vector of the plane.

[0090] The method for integrating data statistics after each bin division is:

[0091] After reading the simulation result file, according to the naming file order, according to the geometric face set screening method, obtain each geometric face [face i,j ,area i,j ] on the statistical information;

[0092] According to the geometric boundary area of ​​the circular surface contained in the naming file i,j , divide each geometric surface into n face elements, read the preset relative coordinate file according to the coordinates of the divided nodes, and i,j Determine the center coordinates, diameter and normal vector to translate, scale and rotate the coordinates;

[0093] The simulation value X at the centroid position of each surface element i is read by interpolation method i , based on area A i The average simulation value of each facet is calculated by weighted method And calculate the average simulation value The distribution uniformity of X and mass flow

[0094] All data statistics are combined into format, and stored as corresponding accompanying files according to the number of nozzle surfaces stored.

[0095] The method for calculating the uniformity of the statistical distribution of each nozzle surface is:

[0096] Obtain the corresponding statistics on the j+1 faces of each nozzle i;

[0097] According to the uniformity calculation formula, the distribution uniformity of each statistical physical quantity on the central nozzle surface of each ring nozzle is obtained.

[0098] The same calculation method is used to determine the distribution uniformity of the remaining surface statistics after averaging them by surface;

[0099] The statistical physical quantities on the central nozzle surface of all nozzles are obtained, and the distribution uniformity is calculated. The distribution uniformity of the statistical quantities on the remaining surfaces after being averaged by the surface is determined by the same calculation method.

[0100] When the reorganized collection faces are re-represented in Or reorganize the collection faces out Including the center nozzle surface When the center nozzle surface is named type_in_1_1_1, in represents the inlet, and the three digits represent the number of rings, the number of nozzle surface groups, and the center surface respectively;

[0101] Select any face in face_ring2 as the starting face for ring sorting and name it type_in_2_1_1, where in represents the inlet and the three digits represent the number of rings, the number of nozzle face groups, and the center face respectively.

[0102] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0103] In the current embodiment, the method for sorting and marking the spatial discrete grid surface and statistically analyzing the simulation uniformity mainly includes three parts, namely, geometric model pre-processing, simulation calculation and calculation result post-processing, such as Figure 1 As shown, specifically:

[0104] (1) Select the computational simulation geometry model and sort and mark the nozzle surface. The generation of the grid depends on the determined geometric boundary, so the sorting and marking of the spatial discrete grid surface is actually the sorting and marking of the corresponding geometric boundary. Therefore, before the simulation calculation, the sorting and marking of the nozzle surface of the simulation geometry model needs to be completed and stored as an accompanying file.

[0105] (1-a) Determine the geometric model used for mesh drawing simulation analysis;

[0106] (1-b) Split the geometric model, such as Figure 2 As shown, the whole fluid domain is divided into three parts according to the nozzle inlet and nozzle outlet, namely, before the nozzle inlet (distribution cavity), nozzle section, and after the nozzle outlet (combustion area), and topological sharing is performed;

[0107] (1-c) Figure 3 As shown, the geometric faces before the nozzle inlet and after the nozzle outlet are read, and the geometric faces read before the nozzle inlet are recorded as a collection faces in , record the geometric faces read after the nozzle exit as the collection faces out. Then add faces in and faces out According to the geometric size relationship, the faces that do not meet the nozzle surface size are removed, and the faces in and faces out The sum is recorded as the set faces;

[0108] (1-d) Figure 4 As shown, for example, for the collection faces in Contains two types of faces of different relative sizes. It can be seen that its geometric features are smaller N j faces surround the larger N i Therefore, faces in Medium i The faces to be filtered are recorded as faces in1 , the remaining faces are recorded as faces in2 . in1 Each face in in2 The faces in the image are matched according to the ring feature, and this ring of faces surrounds a set of faces (N j +1 face) is recorded as Then reassemble N i indivual for faces in , reassemble the faces in the same way as above out ;

[0109] (1-e) For the j fluid channel in the nozzle numbered i, its inlet and outlet surfaces are recorded as surfaces and The collection faces contains a total of N i ×2×(N j +1) faces, N i is the number of nozzles, (N j +1) is the number of nozzle fluid channels. in in is the center surface of nozzle i, faces out For the same data structure;

[0110] (1-f) Figures 2 to 4 The burner shown includes a center nozzle, but some burners may have a center ignition unit without a nozzle. in For example, before naming and sorting, it is necessary to determine whether there is a central nozzle surface located at the center of all nozzle surface groups. If it exists, name the face group type_in_1_1_1. The naming rule is that in represents the entrance, the first 1 represents the center position, i.e. the first ring, the second 1 represents the first nozzle face group 1 of the ring, and the third 1 represents the first type of face (center face) in the nozzle face group. If the face does not exist, create the reference face and name it according to the rule before c.

[0111] (1-g) with the entrance face group faces in As an example, the distance is compared with the center nozzle surface group, and all nozzle surface groups are classified into N k Ring Group in

[0112] (1-h) Select the ring closest to the center nozzle surface for sorting and naming. Select a surface in face_ring2 as the starting surface for ring sorting and name it type_in_2_1_1. The naming rules are the same as above. Select the remaining surfaces in face_ring2 and name them in counterclockwise order.

[0113] (1-i) For face_ring k>2 The face closest to the ring sorting start face in the k-1 rings is selected as the ring sorting start face, and the remaining faces are sorted counterclockwise, and the sorting and naming of all rings are completed according to the sorting rules in g and h;

[0114] (1-j) The two types of nozzle groups are respectively denoted as and in Attach the geometric boundary features to each nozzle face, namely [face i,j ,area i,j ], area i,j for face i,j The radius of the maximum inscribed circle, the coordinates of the center of the circle and the normal vector of the plane, and finally the faces in and faces out Stored as data file;

[0115] (1-k) Mesh drawing and simulation calculation of the geometric model with completed surface naming;

[0116] (2) Extract the statistical data on each nozzle surface. The final simulation results are mainly concerned with the statistical quantities on each nozzle surface, such as flow rate and various area-weighted or flow-weighted averages. Therefore, it is necessary to extract various statistical quantities on each plane according to the naming order based on the simulation results and accompanying files generated in (1);

[0117] (2-a) Read the simulation result file and the naming file, and obtain each face [face i,j ,area i,j ] is the statistic of interest;

[0118] (2-b) According to the geometric boundary area contained in the naming file i,j (all are circular surfaces), the geometric surface is Figure 5 The method shown is divided into n face elements. The division method is unique and fixed. The coordinates of the division nodes read the predetermined relative coordinate file, and then according to the area i,j The center coordinates, diameter and normal vector are determined to translate, scale and rotate the coordinates. Then the simulation value X at the centroid position of each face element i is read. i (obtained by interpolation method), based on area A i The average simulation value of the surface is calculated by weighted method The distribution uniformity γ of the simulation value on the surface is obtained according to the following formula X , and calculate the mass flow rate

[0119]

[0120] (2-c) For the outlet plane, additional pressure drop after area weighting is calculated;

[0121] (2-d) The statistics of each plane are in the following format Arrange and merge, and store them into files according to the surface storage format of the nozzle surface;

[0122] (3) Calculation of the uniformity of the distribution of statistics on the nozzle surface

[0123] (3-a) Read the file saved in step c in (2) to obtain the corresponding statistics on the j+1 surfaces of each nozzle i;

[0124] (3-b) According to the uniformity calculation formula, the distribution uniformity of each statistical physical quantity on the central nozzle surface of each ring nozzle (including N nozzles) is obtained The remaining surface statistics are averaged by surface and calculated in the same way as the center nozzle surface;

[0125]

[0126] (3-c) Obtain the distribution uniformity of each statistical physical quantity on the central nozzle surface of all nozzles according to the uniformity calculation formula The remaining surface statistics are averaged by surface and calculated in the same way as the center nozzle surface;

[0127]

[0128] (3-d) Check whether the flow distribution, pressure drop and corresponding uniformity parameters meet the design requirements.

[0129] In the field of liquid rocket engines corresponding to this embodiment, in a combustion chamber containing hundreds or thousands of nozzles, a simulation evaluation method for parameters such as flow rate and pressure at the inlet and outlet of each nozzle is quickly performed, including two types of innovative processing: simulation pre-processing and simulation post-processing; at the same time, the innovative processing of geometry during the simulation pre-processing period is a simulation pre-processing method that quickly sorts, classifies and marks thousands of disordered (different from the design logic sorting) grid surfaces containing information to be extracted in the thrust chamber according to the design logic and applies them to the simulation calculation period;

[0130] The innovative processing of geometry during the post-processing period of simulation includes proposing a method to evaluate the multi-dimensional uniformity of simulation (distribution uniformity on each surface, distribution uniformity of multiple nozzles) through the API interface of the post-processing software when the simulation software lacks the statistics of multi-dimensional uniformity of hundreds or thousands of grid surfaces.

[0131] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0132] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for sorting and marking spatial discrete grid surfaces and statistically simulating uniformity, characterized in that include: Establish geometric model for nozzle structure simulation analysis; Divide the geometric model according to the fluid domain on the nozzle surface, filter the geometric surface set, sort and name them, and then store them as accompanying files; Perform simulation calculations based on the accompanying file data, read the simulation calculation results to perform facet division, calculate the average simulation value of each facet after division, calculate the distribution uniformity and mass flow of each facet based on the average simulation value, integrate the calculated data statistics and store them as an accompanying file; Calculate the uniformity of the statistical quantity distribution of each nozzle surface according to the accompanying files stored after integration; According to the calculated distribution uniformity of the statistical quantities of each nozzle surface, the corresponding flow distribution and pressure drop of each nozzle surface, it is judged whether the nozzle structure corresponding to the current geometric model meets the design requirements.

2. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 1, characterized in that: The method to filter the geometric face collection is: The geometric model is divided into the front section of the nozzle inlet, the nozzle inlet, the nozzle section, the nozzle outlet, and the rear section of the nozzle outlet according to the fluid domain on the nozzle surface; Read the geometric faces of the front section of the nozzle inlet and the back section of the nozzle outlet, and record the geometric faces of the front section of the nozzle inlet as a collection of faces in , record the geometric faces read at the nozzle outlet as a collection of faces out , according to the geometric size relationship, the two sets are eliminated from the geometric faces that do not meet the size of the nozzle surface, and recorded as the set faces; For collection faces in , collection faces out The size parameters of each geometric face in the set are divided into surrounding geometric faces, and the larger size parameters are divided into central geometric faces. The surrounding geometric faces and central geometric faces in each set are matched with circular features to obtain the reorganized set faces. in , reorganize the collection faces out ; Read the fluid channel numbered j in the nozzle segment numbered i, and record the inlet and outlet surfaces as and Reorganize the collection faces according to the entry and exit faces in , reorganize the collection faces out Re-represent the data structure; Reorganized collection faces after re-representation in , reorganize the collection faces out Determine the position of the center nozzle surface. If there is a center nozzle surface where the center nozzle is set Then mark the group name, if it does not exist, create a center nozzle surface containing the center nozzle Simultaneously name a mark or create a center nozzle face According to other geometrical surfaces and the central nozzle surface or The distance between the two geometric faces is classified as N k Ring Group or Select the surrounding geometric faces closest to the center nozzle face for sorting and naming, select any face in face_ring2 as the starting face for ring sorting and mark it after naming, and sort and name the remaining surrounding geometric faces in face_ring2 in a counterclockwise order; For the geometric faces in face_ring2, select the geometric face closest to the ring sorting start face in the k-1th ring as the ring sorting start face, and sort the remaining geometric faces counterclockwise to complete the ring sorting and naming of all geometric faces; The two types of nozzle surface sets are denoted as and Add geometric boundary features to each nozzle face and add the features to the collection faces. in and faces out Stored as data file.

3. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 2, characterized in that: For collection faces in , collection faces out The method for matching the annular features of the surrounding geometric surface and the central geometric surface is as follows: The collection faces in N with larger size parameter i The central geometric faces are labeled as faces in1 , the size parameter N is smaller j The surrounding geometric faces are labeled as faces in2 , the collection faces in1 Each geometric face in the collection is in2 The geometric faces in the N j +1 geometric face matching, the next set is recorded as Recombination N i indivual For collection faces in , while recombining N i indivual For collection faces in ; The collection faces out N with larger size parameter i The central geometric faces are labeled as faces out , the size parameter N is smaller j The surrounding geometric faces are labeled as faces out2 , the collection faces out1 Each geometric face in the collection is out2 The geometric faces in the N j +1 geometric face matching, the next set is recorded as Recombination N i indivual For collection faces out , while recombining N i indivual For collection faces out .

4. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 3, characterized in that: The collection faces includes N i ×2×(N j +1) faces, N i is the number of nozzles, (N j +1) is the number of nozzle fluid channels; after re-expression: In the formula, is the center plane of nozzle i; In the formula, is the center plane of nozzle i.

5. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 3, characterized in that: The geometric boundary features are: [face i,j ,area i,j ], area i,j for face i,j The radius of the largest inscribed circle, the coordinates of the center of the circle and the normal vector of the plane.

6. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 3, characterized in that: The method for integrating data statistics after each bin division is: After reading the simulation result file, according to the naming file order, according to the geometric face set screening method, obtain each geometric face [face i,j ,area i,j ] on the statistical information; According to the geometric boundary area of ​​the circular surface contained in the naming file i,j , divide each geometric surface into n face elements, read the preset relative coordinate file according to the coordinates of the divided nodes, and i,j Determine the center coordinates, diameter and normal vector to translate, scale and rotate the coordinates; The simulation value X at the centroid position of each surface element i is read by interpolation method i , based on area A i The average simulation value of each facet is calculated by weighted method And calculate the average simulation value The distribution uniformity of X and mass flow All data statistics are combined into format, and stored as corresponding accompanying files according to the number of nozzle surfaces stored.

7. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 6, characterized in that: The method for calculating the uniformity of the statistical distribution of each nozzle surface is: Obtain the corresponding statistics on the j+1 faces of each nozzle i; According to the uniformity calculation formula, the distribution uniformity of each statistical physical quantity on the central nozzle surface of each ring nozzle is obtained. The same calculation method is used to determine the distribution uniformity of the remaining surface statistics after averaging them by surface; The statistical physical quantities on the central nozzle surface of all nozzles are obtained, and the distribution uniformity is calculated. The distribution uniformity of the statistical quantities on the remaining surfaces after being averaged by the surface is determined by the same calculation method.

8. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 7, characterized in that: The distribution uniformity of each statistical physical quantity on the central nozzle surface of each ring nozzle Specifically: Wherein, the number of nozzles is N.

9. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 7, characterized in that: The calculation method of the distribution uniformity of the statistical physical quantity corresponding to the central nozzle surface of all nozzles is:

10. The method for sorting and marking spatial discrete grid surfaces and performing statistical simulation uniformity according to claim 7, characterized in that: When the reorganized collection faces are re-presented in Or reorganize the collection faces out Including the center nozzle surface When the center nozzle surface is named type_in_1_1_1, in represents the inlet, and the three digits represent the number of rings, the number of nozzle surface groups, and the center surface respectively; Select any face in face_ring2 as the starting face for ring sorting and name it type_in_2_1_1, where in represents the inlet and the three digits represent the number of rings, the number of nozzle face groups, and the center face respectively.

Images